The present invention relates to laundry detergent compositions containing a combination of anionic, specified nonionic and cationic surfactants giving improved oily soil detergency.
Heavy duty laundry detergent compositions have for many years contained anionic sulphonate or sulphate surfactant, for example, linear alkylbenzene sulphonate (LAS), together with ethoxylated nonionic surfactants. Examples abound in the published literature.
The preferred ethoxylated alcohol nonionic surfactants giving an optimum balance of properties have generally been those having an alkyl chain length of C12-C15 and an average degree of ethoxylation of 1 to 10, preferably 3 to 7, more preferably about 5.
Longer-chain alcohols having a higher degree of ethoxylation, for example, tallow alcohol (C18) 11EO, have also been used.
These relatively hydrophobic materials of low HLB value are generally liquids at ambient temperature and exhibit excellent oily soil removal. Longer-chain alcohols having higher degrees of ethoxylation, for example, tallow (C18) alcohol 25EO and 50EO, are solids at ambient temperature and are used as slowly dissolving coating materials, for example, for enzyme or antifoam granules.
Laundry detergent compositions containing cationic (quaternary ammonium) surfactants in combination with anionic and nonionic surfactants are widely disclosed in the patent literature.
It has now surprisingly been found that the combination of anionic and cationic surfactants together with ethoxylated alcohols combining a shorter alkyl chain length and a higher degree of ethoxylation can give enhanced oily soil removal.
WO 94 16052A (Unilever) discloses high bulk density laundry powders based on LAS and conventional nonionic surfactants, and containing small amounts of very highly ethoxylated alcohols, eg tallow alcohol 80EO, as a dissolution aid.
WO 93 02176A (Henkel) discloses the use of highly ethoxylated aliphatic alcohols as xe2x80x9cstructure breakersxe2x80x9d in high bulk density powders containing conventional nonionic surfactants.
EP 293 139A (Procter and Gamble) discloses twin-compartment sachets containing detergent powders. Some powders contain very small amounts of tallow alcohol 25EO.
U.S. Pat. No. 4,294,711 (Procter and Gamble) discloses a textile softening heavy duty detergent composition containing 1 wt % of tallow alcohol 80EO.
WO 92 18594A (Procter and Gamble) discloses builder granules of layered silicate coated with tallow alcohol 50EO.
EP 142 910A and EP 495 345A (Procter and Gamble) disclose antifoam granules containing highly ethoxylated alcohols.
WO 93 19148A (Procter and Gamble) discloses liquid hard surface cleaning compositions containing highly ethoxylated nonionic surfactants optionally plus anionic surfactant.
WO 97 43364, WO 97 43365A, WO 97 43371A, WO 97 43387A, WO 97 43389A, WO 97 43390A, WO 97 43391A and WO 97 43393A, (Procter and Gamble) disclose laundry detergent compositions containing so-called xe2x80x9cAQAxe2x80x9d alkoxylated quaternary ammonium surfactants in combination with other surfactants.
The present invention provides a built laundry detergent composition comprising
(i) from 5 to 40 wt %, preferably from 7 to 30 wt %, of surfactant consisting essentially of:
(i)(a) an anionic sulphonate or sulphate surfactant,
(i)(b) an ethoxylated alcohol nonionic surfactant of the general formula I
Rxe2x80x94(xe2x80x94Oxe2x80x94CH2xe2x80x94CH2)nxe2x80x94OHxe2x80x83xe2x80x83(I) 
xe2x80x83wherein R is a hydrocarbyl chain having from 8 to 16 carbon atoms, and the average degree of ethoxylation n is from 20 to 50,
(i)(c) a quaternary ammonium cationic surfactant,
(ii) from 10 to 80 wt % of detergency builder,
(iii) optionally other detergent ingredients to 100 wt %.
The invention also provides a process for laundering textile fabrics by machine or hand, which includes the step of immersing the fabrics in a wash liquor comprising water in which a laundry detergent composition as defined in the previous paragraph is dissolved or dispersed.
The invention further provides the use of a surfactant (i) consisting essentially of
(i)(a) an anionic sulphonate or sulphate surfactant,
(i)(b) an ethoxylated alcohol nonionic surfactant of the general formula I
Rxe2x80x94(xe2x80x94Oxe2x80x94CH2xe2x80x94CH2)nxe2x80x94OHxe2x80x83xe2x80x83(I) 
xe2x80x83wherein R is a hydrocarbyl chain having from 8 to 16 carbon atoms, and the average degree of ethoxylation n is from 20 to 50,
(i)(c) a quaternary ammonium cationic surfactant, in a laundry detergent composition in an amount of from 5 to 40 wt %, to improve the oily soil detergency of the composition.
The detergent compositions of the invention contain a combination of an anionic sulphonate or sulphate surfactant, a defined nonionic surfactant, and a cationic surfactant. The total amount of the three surfactants is from 5 to 40 wt %, preferably from 7 to 30 wt %.
Detergent compositions according to the invention show improved oily soil detergency across a range of fabrics and water hardnesses.
The Anionic Surfactant (i)(a)
The anionic surfactant is a sulphonate or sulphate anionic surfactant.
Anionic surfactants are well-known to those skilled in the art. Many suitable detergent-active compounds are available and are fully described in the literature, for example, in xe2x80x9cSurface-Active Agents and Detergentsxe2x80x9d, Volumes I and II, by Schwartz, Perry and Berch.
Examples include alkylbenzene sulphonates, primary and secondary alkylsulphates, particularly C8-C15 primary alkyl sulphates; alkyl ether sulphates; olefin sulphonates; alkyl xylene sulphonates; dialkyl sulphosuccinates; and fatty acid ester sulphonates. Sodium salts are generally preferred.
Preferably the anionic surfactant is linear alkylbenzene sulphonate or primary alcohol sulphate. More preferably the anionic surfactant is linear alkylbenzene sulphonate.
The Ethoxylated Nonionic Surfactant (i)(b)
The nonionic surfactant is an ethoxylated aliphatic alcohol of the formula
Rxe2x80x94(xe2x80x94Oxe2x80x94CH2xe2x80x94CH2)nxe2x80x94OH 
wherein R is a hydrocarbyl chain having from 8 to 16 carbon atoms, and the average degree of ethoxylation n is from 20 to 50.
The hydrocarbyl chain, which is preferably saturated, preferably contains from 10 to 16 carbon atoms, more preferably from 12 to 15 carbon atoms. In commercial materials containing a spread of chain lengths, these figures represent an average.
The alcohol may be derived from natural or synthetic feedstock. Preferred alcohol feedstocks are coconut, predominantly C12-C14, and oxo C12-C15 alcohols. Longer chain materials such as tallow or hardened tallow (C18) are not preferred.
The average degree of ethoxylation ranges from 20 to 50, preferably from 25 to 40.
Preferred materials have an average alkyl chain length of C12-C16 and an average degree of ethoxylation of 25 to 40.
An example of a suitable commercially available material is Lutensol (Trade Mark) AO30, ex BASF, which is a C13-C15 alcohol having an average degree of ethoxylation of 30.
The Cationic Surfactant (i)(c)
Preferred water-soluble cationic surfactants are quaternary ammonium salts of the general formula II
R1R2R3R4N+Xxe2x88x92xe2x80x83xe2x80x83(II) 
wherein R1 is a relatively long (C8-C18) hydrocarbon chain, typically an alkyl, hydroxyalkyl or ethoxylated alkyl group, optionally interrupted with a heteroatom or an ester or amide group; each of R2, R3 and R4 (which may be the same or different) is a short-chain (C1-C3) alkyl or substituted alkyl group; and X is a solubilising anion, for example a chloride, bromide or methosulphate ion.
According to a first preferred embodiment of the invention, the cationic surfactant is a quaternary ammonium compound of the formula II in which R1 is a C8-C18 alkyl group, more preferably a C8-C10 or C12-C4 alkyl group, R2 is a methyl group, and R3 and R4, which may be the same or different, are methyl or hydroxyethyl groups. Such compounds have the formula III: 
In an especially preferred compound, R1 is a C12-C14 alkyl group, R2 and R3 are methyl groups, R4 is a 2-hydroxyethyl group, and Xxe2x88x92 is a chloride ion. This material is available commercially as Praepagen (Trade Mark) HY from Clariant GmbH, in the form of a 40 wt % aqueous solution.
According to a second preferred embodiment of the invention, the cationic surfactant is an ethoxylated quaternary ammonium compound of the formula IV: 
wherein
R5 is a C6-C20 alkyl group,
m is an integer from 1 to 20,
R6 and R7, which may be the same or different, each represents a C1-C4 alkyl group or a C2-C4 hydroxyalkyl group,
R8 represents a C1-C4 alkyl group, and
Yxe2x88x92 represents a monovalent solubilising anion.
In preferred ethoxylated cationic surfactants of the formula IV used in accordance with the invention,
R5 is a C10-C6 alkyl group,
m is from 1 to 4,
R6, R7 and R8 are methyl groups, and
Yxe2x88x92 represents Clxe2x88x92.
An especially preferred ethoxylated cationic surfactant used in accordance with the present invention is of the formula IV in which
R5 is a C12-C14 alkyl group,
m is 3,
R6, R7 and R8 are methyl groups, and
Yxe2x88x92 represents Clxe2x88x92.
This material (DBETAC) has the formula V 
wherein R9 is a C12-C14 alkyl group.
Other classes of cationic surfactant include cationic esters (for example, choline esters).
The Surfactant Combination (i)
The surfactant combination preferably consists essentially of:
(i)(a) from 20 to 98 wt % of the anionic sulphonate or sulphate detergent;
(i)(b) from 1 to 60 wt % of the nonionic surfactant, and
(i)(c) from 1 to 60 wt % of the cationic surfactant.
The whole product preferably contains from:
(i)(a) from 1 to 20 wt % of the anionic sulphonate or sulphate detergent;
(i)(b) from 0.5 to 20 wt % of the nonionic surfactant, and
(i)(c) from 0.1 to 20 wt % of the cationic surfactant.
Preferred weight ratios are as follows:
In the first preferred embodiment of the invention wherein the cationic surfactant is a compound of the formula III, then the surfactant system is preferably composed as follows:
(i)(a) from 50 to 98 wt %, preferably from 60 to 95 wt %, of the anionic sulphonate or sulphate detergent;
(i)(b) from 1 to 30 wt %, preferably from 5 to 25 wt %, of the nonionic surfactant, and
(i)(c) from 1 to 30 wt %, preferably from 5 to 25 wt %, of the cationic surfactant.
The whole product preferably contains:
(i)(a) from 3 to 30 wt %, preferably from 5 to 25 wt %, of the anionic sulphonate or sulphate detergent;
(i)(b) from 0.5 to 10 wt %, preferably from 1 to 5 wt %, of the nonionic surfactant, and
(i)(c) from 0.1 to 10 wt %, preferably from 0.2 to 5 wt %, of the cationic surfactant.
Preferred weight ratios are as follows:
In the second preferred embodiment of the invention wherein the cationic surfactant is an ethoxylated compound of the formula IV, then the surfactant system is preferably composed as follows:
(i)(a) from 20 to 80 wt %, preferably from 30 to 60 wt %, of the anionic sulphonate or sulphate detergent;
(i)(b) from 5 to 40 wt %, preferably from 10 to 30 wt %, of the nonionic surfactant, and
(i)(c) from 10 to 60 wt % preferably from 20 to 50 wt %, of the cationic surfactant.
The whole product preferably contains:
(i)(a) from 3 to 30 wt %, preferably from 5 to 25 wt %, of the anionic sulphonate or sulphate detergent;
(i)(b) from 0.5 to 10 wt %, preferably from 1 to 5 wt %, of the nonionic surfactant, and
(i)(c) from 0.1 to 10 wt %, preferably from 0.2 to 5 wt %, of the cationic surfactant.
Preferred weight ratios are as follows:
Optionally minor, non-interfering amounts of other surfactants may also be present. Preferably, however, the composition is free from nonionic surfactants other than the defined nonionic surfactant (i)(b).
More preferably the composition is substantially free of other non-soap surfactants.
Optionally soap may also be present, for example, in an amount of from 1 to 5 wt %.
Detergency Builder (ii)
The compositions may suitably contain from 10 to 80%, preferably from 15 to 70% by weight, of detergency builder. Preferably, the quantity of builder is in the range of from 15 to 50% by weight.
Preferably the builder is selected from sodium tripolyphosphate, zeolite, sodium carbonate, sodium citrate, layered silicate, and combinations of these.
The zeolite used as a builder may be the commercially available zeolite A (zeolite 4A) now widely used in laundry detergent powders. Alternatively, the zeolite may be maximum aluminium zeolite P (zeolite MAP) as described and claimed in EP 384 070B (Unilever), and commercially available as Doucil (Trade Mark) A24 from Ineos Silicas Ltd, UK. Zeolite MAP is defined as an alkali metal aluminosilicate of zeolite P type having a silicon to aluminium ratio not exceeding 1.33, preferably within the range of from 0.90 to 1.33, preferably within the range of from 0.90 to 1.20.
Especially preferred is zeolite MAP having a silicon to aluminium ratio not exceeding 1.07, more preferably about 1.00. The particle size of the zeolite is not critical. Zeolite A or zeolite MAP of any suitable particle size may be used.
Also preferred according to the present invention are phosphate builders, especially sodium tripolyphosphate. This may be used in combination with sodium orthophosphate, and/or sodium pyrophosphate.
Other inorganic builders that may be present additionally or alternatively include sodium carbonate, layered silicate, amorphous aluminosilicates.
Organic builders that may be present include polycarboxylate polymers such as polyacrylates and acrylic/maleic copolymers; polyaspartates; monomeric polycarboxylates such as citrates, gluconates, oxydisuccinates, glycerol mono-di- and trisuccinates, carboxymethyloxysuccinates, carboxy-methyloxymalonates, dipicolinates, hydroxyethyliminodiacetates, alkyl- and alkenylmalonates and succinates; and sulphonated fatty acid salts.
Organic builders may be used in minor amounts as supplements to inorganic builders such as phosphates and zeolites. Especially preferred supplementary organic builders are citrates, suitably used in amounts of from 5 to 30 wt %, preferably from 10 to 25 wt %; and acrylic polymers, more especially acrylic/maleic copolymers, suitably used in amounts of from 0.5 to 15 wt %, preferably from 1 to 10 wt %.
Builders, both inorganic and organic, are preferably present in alkali metal salt, especially sodium salt, form.
Other Detergent Ingredients
As well as the surfactants and builders discussed above, the compositions may optionally contain bleaching components and other active ingredients to enhance performance and properties.
These optional ingredients may include, but are not limited to, any one or more of the following: soap, peroxyacid and persalt bleaches, bleach activators, sequestrants, cellulose ethers and esters, other antiredeposition agents, sodium sulphate, sodium silicate, sodium chloride, calcium chloride, sodium bicarbonate, other inorganic salts, fluorescers, photobleaches, polyvinyl pyrrolidone, other dye transfer inhibiting polymers, foam controllers, foam boosters, acrylic and acrylic/maleic polymers, proteases, lipases, cellulases, amylases, other detergent enzymes, citric acid, soil release polymers, fabric conditioning compounds, coloured speckles, and perfume.
Detergent compositions according to the invention may suitably contain a bleach system. The bleach system is preferably based on peroxy bleach compounds, for example, inorganic persalts or organic peroxyacids, capable of yielding hydrogen peroxide in aqueous solution. Suitable peroxy bleach compounds include organic peroxides such as urea peroxide, and inorganic persalts such as the alkali metal perborates, percarbonates, perphosphates, persilicates and persulphates. Preferred inorganic persalts are sodium perborate monohydrate and tetrahydrate, and sodium percarbonate. Especially preferred is sodium percarbonate having a protective coating against destabilisation by moisture. Sodium percarbonate having a protective coating comprising sodium metaborate and sodium silicate is disclosed in GB 2 123 044B (Kao).
The peroxy bleach compound is suitably present in an amount of from 5 to 35 wt %, preferably from 10 to 25 wt %.
The peroxy bleach compound may be used in conjunction with a bleach activator (bleach precursor) to improve bleaching action at low wash temperatures. The bleach precursor is suitably present in an amount of from 1 to 8 wt %, preferably from 2 to 5 wt %.
Preferred bleach precursors are peroxycarboxylic acid precursors, more especially peracetic acid precursors and peroxybenzoic acid precursors; and peroxycarbonic acid precursors. An especially preferred bleach precursor suitable for use in the present invention is N,N,Nxe2x80x2,Nxe2x80x2-tetracetyl ethylenediamine (TAED). Also of interest are peroxybenzoic acid precursors, in particular, N,N,N-trimethylammonium toluoyloxy benzene sulphonate.
A bleach stabiliser (heavy metal sequestrant) may also be present. Suitable bleach stabilisers include ethylenediamine tetraacetate (EDTA) and the polyphosphonates such as Dequest (Trade Mark), EDTMP.
The detergent compositions may also contain one or more enzymes. Suitable enzymes include the proteases, amylases, cellulases, oxidases, peroxidases and lipases usable for incorporation in detergent compositions.
In particulate detergent compositions, detergency enzymes are commonly employed in granular form in amounts of from about 0.1 to about 3.0 wt %. However, any suitable physical form of enzyme may be used in any effective amount.
Antiredeposition agents, for example cellulose esters and ethers, for example sodium carboxymethyl cellulose, may also be present.
The compositions may also contain soil release polymers, for example sulphonated and unsulphonated PET/POET polymers, both end-capped and non-end-capped, and polyethylene glycol/polyvinyl alcohol graft copolymers such as Sokolan (Trade Mark) HP22. Especially preferred soil release polymers are the sulphonated non-end-capped polyesters described and claimed in WO 95 32997A (Rhodia Chimie).
Product Form and Preparation
The compositions of the invention may be of any suitable physical form, for example, particulates (powders, granules, tablets), liquids, pastes, gels or bars.
According to one especially preferred embodiment of the invention, the detergent composition is in particulate form.
Powders of low to moderate bulk density may be prepared by spray-drying a slurry, and optionally postdosing (dry-mixing) further ingredients. xe2x80x9cConcentratedxe2x80x9d or xe2x80x9ccompactxe2x80x9d powders may be prepared by mixing and granulating processes, for example, using a high-speed mixer/granulator, or other non-tower processes.
Tablets may be prepared by compacting powders, especially xe2x80x9cconcentratedxe2x80x9d powders.
Also preferred are liquid detergent compositions, which may be prepared by admixing the essential and optional ingredients in any desired order to provide compositions containing the ingredients in the the requisite concentrations.